std::imag(std::complex)
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                    | Defined in header  <complex> | ||
| (1) | ||
| template< class T >  T imag( const std::complex<T>& z ); | (until C++14) | |
| template< class T >  constexpr T imag( const std::complex<T>& z ); | (since C++14) | |
| Additional overloads (since C++11) | ||
| Defined in header  <complex> | ||
| (A) | ||
| float       imag( float f ); double      imag( double f ); | (until C++14) | |
| constexpr float       imag( float f ); constexpr double      imag( double f ); | (since C++14) (until C++23) | |
| template< class FloatingPoint > FloatingPoint imag( FloatingPoint f ); | (since C++23) | |
| (B) | ||
| template< class Integer >  double imag( Integer i ); | (until C++14) | |
| template< class Integer >  constexpr double imag( Integer i ); | (since C++14) | |
1) Returns the imaginary part of the complex number z, i.e. z.imag().
| A,B) Additional overloads are provided for all integer and floating-point types, which are treated as complex numbers with zero imaginary part. | (since C++11) | 
Parameters
| z | - | complex value | 
| f | - | floating-point value | 
| i | - | integer value | 
Return value
1) The imaginary part of z.
A) decltype(f){} (zero).
B) 0.0.
Notes
The additional overloads are not required to be provided exactly as (A,B). They only need to be sufficient to ensure that for their argument num:
-  If num has a standard(until C++23) floating-point type T, then std::imag(num) has the same effect as std::imag(std::complex<T>(num)).
- Otherwise, if num has an integer type, then std::imag(num) has the same effect as std::imag(std::complex<double>(num)).
See also
| accesses the imaginary part of the complex number (public member function) | |
| returns the real part (function template) | |
| C documentation for cimag | |